Financially beleaguered Nicolas Cage already owes $6.3 million in back taxes and has begun selling off his homes and yachts. Now Christina Fulton, mother of Cage’s son, Weston, 18, is suing the star for $13 million, claiming he promised to pay off her $250,000 credit-card debt. She also claimed that Cage pro vided her and their son with an LA home, but she has now been hit by an eviction notice, and owes the IRS more than $1 million. She blames Cage for it. Cage says he faces financial ruin after a former ac countant allegedly duped him. The accountant has countersued, claiming Cage’s problems are due to his “com pulsive, self-destructive spending.”